Half-Life isn't free; you need to buy it. Internet play requires a CD
Key number, which only comes with a Half-Life CD. You can't really
share CD Keys because they are authenticated before you begin an internet
game.

Why Customize Mouse Buttons?

You come around a corridor only to find an opponent looking the
other direction or out a window. It's a perfect chance to sneak
up and whack them with the crowbar! You creep up behind them and
reach for the "1" key, but instead of a crowbar you hit the "q"
key. Or, worse, the "~" and bring down the console. Next thing you
know, you're dead.

If only there were a fast and reliable way to grab that crowbar
every time...

Well, if you have a mouse with more than two buttons, there is!
In the section below I'll show you how to bind mouse buttons to
Half-Life game actions such as "use the crowbar".

The standard Half-Life configuration assigns mouse buttons 1 and
2 to "fire" and "secondary fire", respectively. But three-button
mice have been common for years, and nowadays it's very common to
have five buttons plus a wheel. Don't let those buttons go to waste.
Use of the wheel is configured by default in current Half-Life versions,
but you have to do a little work to take advantage of mouse buttons
3, 4, and 5.

I currently use the Microsoft Intellimouse Optical shown above
and have been very pleased with it. Some sources incorrectly describe
this as a "2 button" mouse. If in doubt, check the part
number: D58-00002 is the 5-button mouse shown above.

My opinion is that the more-expensive Microsoft optical Intellimouse
Explorer is an inferior choice for game play. The Intellimouse
Explorer is an asymmetrical "right-handed" mouse (I've
never seen a left version) with buttons 4 and 5 both located on
its left-hand side, for operation by your right thumb.

How To Set Half-Life Mouse Button
Bindings

First, here is the basic information you need to know about how
your Half-Life game configuration can be modified.

Key and button bindings are set in the text file config.cfg
which lives in your Half-Life\valve\ directory. You can
edit it with your favorite text editor. Notepad works fine.

Inside config.cfg, the syntax for binding an action
to a key event is

bind eventnameaction

The eventnames for the mouse button-press events are
MOUSE1, MOUSE2, MOUSE3, MOUSE4, MOUSE5. The wheel events
are named MWHEELDOWN and MWHEELUP

Everything you can do in Half-Life is an action. The
particular ones we need to look at are

use item

Uses an item or weapon. Weapons all have names such as
"weapon_crowbar" (see list at right
in sidebar).

lastinv

Toggle between the two most recently used "inventory items".
For our purposes, that just means switching between the last
two weapons. lastinv is normally bound to the "q"
key.

invnext

Select the next inventory item (i.e. weapon). invnext
is normally bound to the "]" key.

invprev

Select the previous inventory item. invprev
is normally bound to the "[" key.

+reload

Reload the current weapon. Normally bound to the "r"
key.

+attack

Fire weapon. Normally bound to mouse button 1.

+attack2

Alternate weapons fire. Normally bound to mouse button 2.

For much more information about Half-Life configuration syntax
and console commands, visit the Command
Center.

So, for example, if you open your config.cfg file you'll
find the following line (unless it has been changed):

bind "MOUSE1" "+attack"

This is how mouse button 1 is bound to the "fire" action.
The standard config file uses double-quotes around each argument.

Example: The Big Tweeze's Favorite
Mouse Button Bindings

Button assignment on The Big Tweeze's mouse.

Most importantly, I want to be able to grab the crowbar quickly,
and I always fumble for the "1" key, so I've assigned the left side
button (MOUSE4) like this:

bind "MOUSE4" "use weapon_crowbar"

I tend to fumble the "q" key (usually bound to lastinv,
toggle between last two weapons), so instead I like to use the center
mouse button (MOUSE3) for this purpose. I bind it to the lastinv
action like this:

bind "MOUSE3" "lastinv"

I also removed the standard binding for the q key so
I don't hit it by mistake. My pal Sweaty binds
MOUSE3 to +reload.

The mouse wheel can be used to scroll through your weapons inventory.
These are now part of the standard configuration:

bind "MWHEELDOWN" "invnext"
bind "MWHEELUP" "invprev"

The remaining question is what to do with the right side mouse
button, MOUSE5. I tried using it to select the satchel charge, but
that has not worked very well for me. Sweaty has
MOUSE5 bound to the machine gun and he's been whupping me lately,
so that might be a good one to try. Currently I'm trying it with
the shotgun:

bind "MOUSE5" "use weapon_shotgun"

All you have to do is edit config.cfg with your favorite
text editor and add these lines. Put them next to the existing MOUSE
lines. Never be afraid again to switch to "The Bar" in close combat!

A 5-button mouse with wheel can give you a real advantage in Half-Life. Pictured above is the
IntelliMouse Optical
by Microsoft, the favored choice of Tweezer's
Half-Life Health Club. Optical mice track better, with no
ball or rollers to gum up. The Intellimouse Optical retails for
$55.

You may prefer the Intellimouse Explorer, which has a different button
arrangement. It lists for $20 more, but actually cost only about
$6 more when I checked PCMall.com.